FBA: Point a new web app to the same user store

I'm redesigning our site under a new web app. I've configured it to point to the same FBA user store, but I am a little confused on where the "Full Name" is stored at. Right now, the old site has all the full names, while the new site
(pointed to the same user store) only contains the usernames, which is not real helpful when trying to add people to groups.